Multiple-billet mold



Nov. 29, 1966 H. SCHREWE MULTIPLE-BILLET MOLD 4 Sheets-Sheet 1 Filed Feb. 25, 1964 Fig. 4

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N0V 29, 1966 H. scHREwE 3,287,770

MULTIPLE-BILLET MOLD Filed Feb. 25, 1964 4 Sheets-Sheet 2 79ans Sc reamel Nov. 29, 1966 H. scHREwr-z 4 Sheets-Sheet 3 Fig. 7

`7n ven for #Ms Screwe/ Nov. 29, 1966 H. SCHREWE 3,287,770

MULTIPLE-BILLET MOLD Filed Feb. 25, 1964 4 Sheets-Sheet 4 "5 Ffg. 6

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United States Patent Office 3,287,770 MULTIPLE-BILLET MOLD Hans Schrewe, Duisburg, Germany, assigner to Mannesmann Aktiengesellschaft, Dusseldorf, Germany, a corporatian of Germany Filed Feb. 25, 1964, Ser. No. 347,161 Claims priority, application Germany, Feb. 2S, 1963, M 55,938 5 Claims. (Cl. 22-57.2)

The invention relates to continuous metal casting, and relates more particularly to means for improving the grain structure and surface properties of the castings made in multiple-billet molds. Still more particularly, lthe invention relates to multiple-billet molds which are so constructed as to promote the aforesaid improvements in grain structure and surface properties of the castings.

It will be understood that the term continuous casting" used herein includes not only continuous casting but also the art of semi-continuous casting.

In the endeavor to improve the grain structure and surface properties of castings made in a continuous process, certain attempts have been made in the past -to impart a controlled movement to the liquid metal bath within the mold. For example, it is known to impart Ito the liquid metal bath in the mold a movement by means of external forces of either mechanical or electromagnetic nature. Where the cross-sections of the mold are such that the liquid metal must flow through long stretches before the mold has been filled, the foregoing method, however, may lead to objectionable surface characteristics of the castings.

It is furthermore known -to impart to a non-ferrous metal bath in the feeding head of the mold a rotational movement by means of a pipe that conveys the liquid metal and that extends below the level of the liquid metal bath in the mold and which has tangential discharge openings which are disposed below that level. This arrangement, however, is not suitable for the casting of iron or steel. For the continuous casting of iron or steel alloys, it has therefore become known to impart to the molten metal in the feeding head of the mold a horizontal movement and/or a vertical movement, for instance electromagnetically.

The aforesaid methods practiced heretofore are, however, subject to breakdowns, and the apparatus used either are short lived or quite complex, and usually are relatively expensive.

During the casting of square billets of small cross-section, for instance of a width of 100 mm. or less, as well as for corresponding round billets, it is known to cast simultaneously several adjoining billets in a single suitably formed mold. In such a multiple-billet mold, the hollow mold spaces for the individual billets are interconnected by narrow channels that may extend throughout the entire height of the mold. A mold of this type yields a multiplebillet which is subsequently divided lengthwise into its individual sections. For multiple-billet molds of such complexity, the foregoing methods for improvement of the properties of the castings are, however, not suitable.

It is accordingly among the principal objects of the instant invention to promote a uniform grain formation and uniformly good surface properties in castings made in a multiple-billet continuous casting mold.

It is another object of the invention to provide a multiple-billet mold with a plurality of hollow mold spaces which are interconnected in such a manner that the metal ba-th in the mold will be subjected to a movement without, however, applying any external mechanical or electromagnetic force.

3,287,770 Patented Nov.l 29, 1966 It is yet another object of the invention to provide a mold of this type wherein the hollow mold spaces are interconnected in such a way that the liquid metal delivered to one hollow space proceeds therefrom into adjoining spaces in such a manner that the metal flow will impart to the metal bath in said adjoining spaces a rotational movement within the vicinity of the metal level.

It is a further object of the invention lto provide such a mold with interconnecting channels between the adjoining hollow mold spaces in such a manner that the channels will be disposed eccentrically of the centers of the hollow spaces.

It is still another object of the invention to provide such a mold with hollow spaces of polygonal, for instance substantially square cross-section, the channels interconnecting two adjoining hollow spaces entering each space near a corner thereof and in alignment with one of the sides of the space.

It is still a further object of the invention to provide a mold of this type that has the plurality of hollow mold spaces of round cross-section in which each two adjoining spaces are interconnected by a substantially tangentially disposed channel.

Further objects and advantages of the invention will be set forth in part in the following specification and in part will be obvious therefrom without being specifically referred to, the same being realized and attained as pointed out in the claims hereof.

With the above and other objects of the invention in view, the invention consists in the novel construction, arrangement and combination of various devices, elements and parts, as set forth in the claims hereof, certain embodiments of the same being illustrated in the accompanying drawings and described in the specification.

'I'he foregoing and other objects of the invention will be best understood from the following description of exemplications thereof, reference being had to the accompanying drawings, wherein:

FIG. 1 is a plan View of a multiple-billet mold, for squa-red square billets; Y

FIG. 2 is a -plan view similar to FIG. l, but embodying a modification;

FIG. 3 is `a .plan view of a multiple-billet mold for square billets, placed diagonally;

FIG. 4 is a plan View similar to FIG. 3, lbut with one of the hollow spaces off-set from the others;

FIG. 5 is a plan view of a multiple-'billet mold for round billets;

FIG. 6 is a plan View similar to FIG. 5, a modification;

FIG. 7 is a fragmentary Vschematic rear elevational view, partly in section, of a machine for the continuous casting of multiple billets; and

FIG. 8 is a `fragmentary schematic side elevational view, partly in section, of lthe Imachine shown in FIG. 7.

In FIG. l, there is shown a mold for the ycontinuous casting of multiple billets; the mold has a body which includes two parts 1a and 1b that are joined alonlg a major vertical plane, for example the central vertical dividing plane of the mold. A plurality of hollow mold spaces 2 are provided, five -of these ha-ving 'been chosen flor illustration in FIG. l, which are designated 2a, 2b, 2c, ,2d and 2a. The spaces have substantially square cross-sections, and are squared in relation to the aforesaid .central mold plane.

In FIGS. 1-4, the open mol-d spaces for the billets are shown, and described herein below, as having substantially square cross-sections.

In FIGS. 5 and 6, on the other hand, hollow mold but embodying spaces are shown that have substantially circular crosssections.

It is understood, however, that the cross-sections shown were chosen only as illustrative, for the sake of simplicity and clarity, and that instead other prisrnatic or regular or irregular solid or hollow polygonal shapes may be chosen, or shapes with other round cross-sections, including annular or elliptical spaces, for the casting of solid or hollow sections, and also for the casting of mixed hollow-andsolid sections within one multi-ple lbillet, all without departing from the scope of ythe invention save as restricted in the claims hereof.

Each two adioining hollow spaces are interconnected lby means of channels 3 which extend for at least a fraction of, and may extend throughout, the height of the mold. In this manner, Iall the hollow spaces 2 are interconnected to each other, for instance in series, as shown. The discharge mouth of each channel 3 is disposed in a corner of each of the two adjoining hollow spaces that are interconnected .by said channel; the axis of the dischange mouth of each channel 3 is disposed substantially parallel to one of the sides 4 of the square hollow mold space and at ri-ght angle to the aforesaid central plane of the mold.

The length of the channel 3 is best so chosen that the loss of material during the subsequent severing of the lbillets can :be kept las small as possible. The width of fthe channels 3 should 'be in relation to the size of the crosssection of the over-all hollow mold space of the feeding head, respectively, to the casting production capacity tfor the individual billets that adjoin the channels.

In operation, the liquid metal may 4be discharged, for instance into lthe central hollow mold space 2a, and from there the liquid rmetal will proceed through the channels 3 into the two hollow spaces 2b and 2c. -From here the metal will iiow into the outermost hollow spaces 2d and 2e, respectively. The broken line x indicates the ow path of the molten metal 'within the mold, and illustrates `the rotational movement which is generated by `that il-ow in the feeding head of `the mold.

In the modification of FIG. 2, the substantially square hollow spaces 2 are again arranged similar to the arrangement of FIG. 1; but 'the axes of the connecting channels 3 are aligned with the aforesaid vertical central plane of the mold. The operation is similar -to that described inv connection with FIG. 1.

In the embodiments of both FIGS. l and 2, the square hollow spaces 2 are arranged in two rows on Ibo-th sides of the aforesaid central plane yof the mold, showing a total of ve hollow spaces 2. It will the understood, however, that either fewer lor more than iive hollow spaces may Ibe used. It will be furthermore be understood that the number off hollow spaces shown in FIGS. 3-6 are also merely illustrative and not intended -to be restrictive. Lastly, all of the molds are shown vertically straight; it will fbe understood, however, that the instant invention is equally .applicable to multiple-billet molds of the curved type used for the purpose of shifting the descending billet to the horizontal plane.

In the embodiment of FIG. 3, the hollow substantially square spaces 2 are no longer squared with the central plane of the mold, but are arranged diagonally along the central plane; only three hollow spaces 2a, 2b and 2c are shown which are interconnected in series lby the channels .3. The channels 3, like in FIGS. l and 2, interoonnect the hollow spaces 2 near the corners thereof and in line with one of the sides of each square.

In the modification of FIG. 4, there are again shown three square hollow spaces 2, but only two of these, namely the first space 2b and the last space 2c, are shown aligned in the central mold plane, while the middle square 2a is off-set therefrom laterally. The interconnections by means of the channels 3 are similar to those of FIG.

. In FIG. 5 there is shown a multiple-billet mold 1 for round billets of substantially circularNcross-section. The arrangement is similar to that of FIG. 3, except that the channels 3 interconnect the circular hollow space'sw2`, for instance in series, substantially tangentially. While the axes 5 of the channels 3 have been shown in FIG. 5 irl A formation, wherein the axes 5 intersect at an angle, these axes may instead be parallel; where the axes 5 intersect, a preferred arrangement is that they intersect at an angle of about The arrangement of the channels 3 should be so chosen that, depending which of the spaces 2 receives the liquid metal first, the sense of rotation of the lbath in the other hollow spaces to which the liquid hows will alternate. For instance, as shown in the exemplica'tion of FIG. 5, the liquid metal is first poured into the left space 2, and proceeds thence into the middle space where it generates a clockwise bath movement. From the middle space 2 the liquid proceeds into the right space 2 where it generates a counterclockwise movement in the .metal bath.

In FIG. 6 there is shown a three-part mold 1 which defines a central hollow space 2 and -four hollow spaces 2 which are arranged along the lcorners of a square with the central hollow space disposed in the center of that square. Channels 3 again connect the Various hollow spaces, substantially tangentially. The arrangement of FIG. 6 is symmetrical.

The instant invention, for example also provides for the simultaneous casting of almultiple billet, with a solid round billet as the central section and, for instance, two hollow round billets as the side sections.

The casting machine schematicallyV illustrated in FIGS. 7 and 8 shows a ladle 6 below which there is arranged a tundish 7. Below the tundish 7 there is disposed a multiple-billet mold 9 which is supported on an upper machine stage 8. Three round interconnected billets 10 are cast in the machine, similar to the arrangement shown in FIG. 5, and the emerging multiple-billet 10 is engaged by withdrawal rolls 11.

I Wish it `to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

Having thus described the invention, what I claim as new and desire to be secured by Letters Patent, is as follows:

1. A multiple-billet mold for the continuous casting of metal, comprising a mold body defining a plurality of hollow spaces extending throughout the height of the mold body and being open at the top and bottom and forming passages for the continuously cast metal and channels connecting for interior intercommunication each hollow space with at least one other hollow space, said channels extending throughout at least a fraction of the height of the mold, whereby there will lbe continuously cast a single casting each channel being disposed eccentrically relative to the hollow space with which it communicates.

2. A multiple-billet mold, as claimed in claim 1, each hollow space having a polygonal shape, each channel being connected to the corner portion of the hollow space with which it communicates and extending in a direction parallel to one side of the polygonal shape thereof.

3. A multiple-billet mold, as claimed in claim 1, said hollow spaces being round, each channel leading substantially tangentially into the respective hollow spaces with which it communicates.

4. A multiple-billet mold, as claimed in claim 1, said hollow spaces being aligned along a Vertical plane of the mold body.

5. A multiple-billet mold, as claimed in claim 1, said hollow spaces being arranged in two rows oil-set from each other about a vertical plane of the mold body.

(References on following page) ld B References Cited by the Examiner UNITED STATES PATENTS 4/1919 Droege 249-119 4/ 1925 McNelly 249-119 X 2/ 1959 Wieland 22-572 v FOREIGN PATENTS 1,339,997 9/1963 France I. SPENCER OVERHOLSER, Primary Examiner. R. S. ANNEAR, Assistant Examiner. 

1. A MULTIPLE-BILLET MOLD FOR THE CONTINUOUS CASTING OF METAL, COMPRISING A MOLD BODY DEFINING A PLURALITY OF HOLLOW SPACES EXTENDING THROUGHOUT THE HEIGHT OF THE MOLD BODY AND BEING OPEN AT THE TOP AND BOTTOM AND FORMING PASSAGES FOR THE CONTINUOUSLY CAST METAL AND CHANNELS CONNECTING FOR INTERIOR INTERCOMMUNICATION EACH HOLLOW SPACE WITH AT LEAST ONE OTHER HOLLOW SPACE, SAID CHANNELS EXTENDING THROUGHOUT AT LEAST A FRACTION OF THE HEIGHT OF THE MOLD, WHEREBY THERE WILL BE CONTINUOUSLY CAST A SIGNAL CASTING MEACH CHANNEL BEING DISPOSED ECCENTRICALLY RELATIVE TO THE HOLLOW SPACE WITH WHICH IS COMMUNICATES. 